First of all - by the looks of the interior, it does not resemble a true 1984 GN.
The thing that makes an 84 unique is what is called the Lear Siegler interiior, outfitted in leather and Brandon cloth trimmed seats, and many items being colored in what is called "Lt. Sand Grey" - but more beige like.
This car looks to have a more traditional 85/86/87 GN interior done up in the more typical Med Dark Grey / Palex cloth material.
The dash looks to be Md Dark Grey, not Charcoal (black) as was proper for a 84.
The steering wheel looks to be - should I say it?
![Big Grin :D :D](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
I won't say a dime a dozen, but there is nothing all that special about a Med Dark Grey GN interior.
There is that cache about a 1984 GN interior.
Secondly, the only real way to tell if it was originally a GN is by looking at the SPID label, or doing a reconstruction of the window sticker using other tools.
There is nothing in a VIN that designates GN.
Only turbo charged Regal.
So - post a VIN and we can tell you.
Obviously - since it has a LC2 engine - it is not numbers matching.
And that's a plus - since apologies to my HA friends, but the 84 LM9 Hot Air engines are beasts to work on.
Also - even though it has a LC2 motor, you really don't know if it has the properly built trans behind it, either a BRF or a THM200R4 that is modified to BRF standards.
Your question is really one of value
What's an 05 CTS w/ 119K miles on it worth vs a cloned up 1984 Regal with LC2 engine.
The bible for pricing is from Manheim - referred to as MMR
This is only available for the Cadillac, not the Regal due to its age and uniqueness
My rough estimates are:
Cadillac MMR = $5,284 (That is not retail, but what a dealer can buy at auction)
Markups are in the range of $1500-$2000
So, assume maybe about $7K retail for the Caddy - if - it is in avg to better condition
You say $8K - you might be a tad high, but OK.
This car you are looking at I would value at about the same; give or take.
No matter how you slice it - it's a clone in some way shape or form, as it is clearly not factory original.
The value goes either up, down or sideways at that point forward.
Maybe more - if - the engine and trans swap was done professionally or correctly.
Since it requires a new engine harness and other things, and these engines are tempermental even when factory prepared - that's alot of ifs
The paint does looks nice (from afar in pictures) and the interior looks good
Maybe 7-8K, maybe more.
So - a wash - value wise
But two completely different animals.
One can be a daily driver - the other - I'm not so sure.
I'd have to see the Caddy.